SAN DIEGO (AP) — Former U.S. Open champion Sloane Stephens and Karolina Pliskova, a one-time U.S. Open runner-up, won their opening matches at the San Diego Open WTA 500 on Tuesday.

Stephens, a wild-card entrant from the United States who won the 2017 U.S. Open, got her second win in 2022 over lucky loser Jil Teichmann, beating the Swiss lefthander 6-1, 7-6 (2). Pliskova, a former No. 1 from the Czech Republic who was the 2016 U.S. Open runner-up, beat American Caroilne Dolehide 6-3, 6-4 to advance to the second round.

“It’s always a tough match with her. She’s a great player,” said the 52nd-ranked Stephens, who saved a set point in the second set. “I knew she was going to come out and give me a good fight. I just tried to stay calm and play my game. In the end, it went my way.”

Leylah Fernandez, the U.S. Open 2021 runner-up, dropped her second match this year to No. 8 seed Daria Kasatkina, 6-2, 6-2, in just 59 minutes.

“Dasha is an amazing player. She’s improved so much over the years,” Fernandez observed. “I watched her play on TV when I was still a junior. Seeing her now in the top 10 and doing so well this year is truly inspiring. I think today she showed how well she can play. She didn’t make too many mistakes. I, unfortunately, did.”

Croatia’s Donna Vekic beat fifth-seeded Maria Sakkari of Greece for the fifth time in seven meetings, 7-6 (3), 6-1.

“Maria is a really good friend of mine. I wasn’t happy to play her. I think we were both pretty nervous at the beginning, but I managed to calm down a little bit and I think I found my zone in the second set,” said the 77th-ranked Vekic, who now owns nine career wins over Top-10 opponents, including an upset of No. 3 Aryna Sabalenka last summer at the Tokyo Olympics.

“I was really happy when I found out that she took a wild card at the last second and was coming here,” added Vekic. “I texted her straight away. When the draw came out, I was like, ‘Oh, my God, we’re playing each other!’ It’s not easy. We fight on the court, but we’re still close off the court.”

Vekic, 26, finished with seven aces and converted five of six break-point opportunities.